The majority of today's military, industrial, medical, and entertainment applications now process image rich data, dramatically increasing the demand for storage capacity, data transfer rates, and access times. With more applications requiring larger amounts of storage capacity, a gap between required storage capacity and existing storage capacity has developed. For example, a digital versatile disk (DVD) has a capacity of 9.7 GB, whereas an uncompressed high definition television or video (HDTV, HDV) program may require close to 60 GB, and potentially over 100 GB, of data. Accordingly, technological advances are beginning to outpace available storage media.
The disparity in storage capacity in optical storage, in particular, and in secondary storage, in general, is of significant concern. Military and commercial applications previously found only in the realm of supercomputers are now rapidly moving to the desktop and in the home. As a result, there is a growing need for secondary removable storage systems capable of providing fast data transfer rates and access times along with ease of transport for large data files. Optical disk media may be the most cost effective random access means of providing high capacity, high reliability removable storage. As the demand for high capacity storage and fast data transfer rates increases, the storage/processor data transfer bottleneck is rapidly moving closer to the storage media. Therefore, there is a need to increase storage capacity and enhance the data transfer rate of random access high capacity optical storage systems.
Next generation multimedia applications, including training, telemedicine, multi-sensor visualization, and weapons simulation, also need “firehose” access to massive data storage. New microprocessor system architectures and input/output interfaces to provide these connections are becoming available. Interfacing these multimedia applications with data storage systems capable of Gbit/s throughput is now a possibility. For example, multi-fiber networking technologies including 10 G Ethernet are emerging that offer additional bandwidth to and-from storage systems over SAN, LAN, and other high speed networks. Given the 11 Mbit/s transfer rates of current typical to high capacity storage systems, such as DVD storage systems, there is a need to bridge the widening gap between network speeds and transfer rates of storage systems.
Furthermore, military reconnaissance and homeland security systems may require low cost ultra high capacity, on the order of TB/disk, random access removable media capable of high data access rates, e.g., >100 Mbit/s, both for recording and read out to satisfy data streams from multiple sensors, and to provide fast data streams to drive fast parallel search algorithms on the stored data. Historically, engineers have been able to increase the readout and recording data rates for optical disks less than 5% per year. Therefore, it is unlikely that DVD-based systems will be able to satisfy the high data rates required by the aforementioned applications. Magnetic digital tapes are also unlikely to be able to satisfy the above applications since, while they provide very high data rates and capacities, magnetic digital tapes lack random access, thereby making them incompatible with performing fast searches on stored data. Finally, traditional magnetic hard drives provide capacity and reasonably fast data access rates, but are not removable. Removability is, however, critical for image and video processing applications to be implemented at reasonable costs.
Accordingly, a system capable of recording large quantities of data that may be rapidly and randomly accessed is needed.